Patent Number: 6,167,560

Title: One-cold encoding method for low power operation in a complex programmable logic device

Abstract: A method for selecting the state assignments of a complex programmable logic device (CPLD) to minimize power consumption. Within the CPLD, a plurality of macrocells are selected to store a corresponding plurality of state variables, wherein the number of macrocells is selected to be equal to the number of states. For each of the states, one of the macrocells is assigned to store a state variable having a first logic state, and the remaining macrocells are assigned to store state variables having a second logic state. The macrocells storing state variables having the second logic state exhibit a lower power consumption than the macrocell storing the state variable having the first logic state. In addition, each of the macrocells includes a plurality of wired logic gates, each being in a high-current state or a low-current state. The number of wired logic gates in the low-current state is maximized in the macrocells assigned to store the state variables having the second logic state. As a result of these state assignments, the CPLD exhibits a relatively low power consumption.

Inventors: Jenkins, IV; Jesse H. (Danville, CA), Young; Edel M. (Palo Alto, CA)

Assignee: Xilinx, Inc.

International Classification: H03K 19/177 (20060101); G06F 001/02 ()

Expiration Date: 12/26/2017